Adjustable electrosurgical pencil with slidable vent tube

ABSTRACT

An electrosurgical pencil for use in performing surgery on a surgical site includes a main body forming a handle grippable by user and having open front and rear ends. The pencil has a vent tube open at its forward end, and slidably mounted in the body. The tube is adjustable independently from a retracted position to various extended positions. An elongate electrode is mounted in the tube and independently slidable therein. The electrode is adjustable manually in its longitudinal direction from a retracted position to extended positions. A first conducting strip can be mounted in the vent rube in contact with the electrode. A second conducting strip can be mounted in the main body and is in sliding contact with the first strip in order to provide power to the electrode.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation application of U.S. patentapplication Ser. No. 15/996,664, filed on Jun. 4, 2018, which is acontinuation application of U.S. patent application Ser. No. 14/424,795,filed on Feb. 27 (now U.S. Pat. No. 9,987,074), 2015, which is anational stage entry of PCT/CA2013/000741, filed on Aug. 23, 2013, whichclaims the benefit of and priority to U.S. Provisional PatentApplication No. 61/693,826, filed on Aug. 28, 2012. U.S. patentapplication Ser. No. 14/424,795 also claims foreign priority to CanadaPCT CA2012/001200, filed on Dec. 21, 2012. The entire disclosures of allof the foregoing applications are incorporated by reference herein.

BACKGROUND Technical Field

The present application relates to electrosurgical instruments and moreparticularly to electrical surgical pencils for cauterizing tissue andevacuating smoke from a surgical site.

Background of Related Art

The coagulation of blood vessels is a necessary part of medical surgeryand can be performed by an electrosurgical tool commonly known as anelectrosurgical pencil or coagulator pencil. In this type of pencil, anelectrically conductive metal tip either in the form of a blade or aneedle extends outwardly from the forward end of the body of the pencil,the latter acting as a hand grip for a surgeon using the pencil. In use,the tissue of a patient is electrically connected to one side of anelectrosurgical circuit, and the electrically conductive tip isconnected to the other side of this circuit. When the metal tip touchesor is near the tissue at the surgical site, a high frequency electricalcurrent flows from the electrode to the tissue, thus coagulating andcauterizing the tissue. Use of the aforementioned electrosurgical pencilproduces small plumes of smoke which should be removed from the site.This smoke is offensive because of its odor and it is potentiallydangerous to medical personnel. Also evacuation of the smoke is verydesirable so that the surgeon's view of the operation site remainsrelatively unobscured.

Recent U.S. Pat. No. 6,616,658 which issued to the present applicantdescribes an electrosurgical pencil of the aforementioned type. Thisknown pencil has a main body portion forming a handle grippable by auser and having an electrode end and an exhaust end. This pencil comeswith a metal electrode tip having a plastic base and removably mountedin the main body portion. There is an electrical switch in the form of adouble-throw rocker switch mounted on a small circuit board that is inturn mounted within a passage formed in the main body. An elongatesubstantial unobstructed airflow vent is disposed within the bodyportion so as to extend from the electrode end to the exhaust endthereof.

More recent U.S. Pat. No. 7,537,594 to J. D. Sartor describes anelectrosurgical suction coagulator that includes a handle and anelongate tube electrode or conductive suction tube extending from afront end of the handle. The suction tube has a closed distal end and anelongate slot disposed therealong for slidably receiving a needleelectrode which is selectively extendable relative to the closed distalend to facilitate precise dissection. An aspiration port is disposedalong a side of the suction tube for removing surgical fluids. In oneversion of this known coagulator the suction tube is slidingly androtatably received within a channel formed in the handle of the device.A control rod is mechanically coupled to the suction tube and can bemanipulated by the user to extend, retract and/or rotate the suctiontube. The user can also manipulate the needle electrode via anothercontrol rod which operates in a similar manner.

The electrosurgical pencil described herein has both an elongate venttube which can be readily adjusted in its longitudinal directionmanually by the surgeon and also an elongate electrode tool which isadjustable independently in its longitudinal direction by manuallypulling on a projecting forward section of the electrode tool.

SUMMARY

In accordance with one aspect of the present application, anelectrosurgical tool for use in performing surgery on a surgical siteincludes a main body forming a handle for a user and having a first endforming a front opening and an opposite second end forming an exhaustopening. The main body defines an airflow vent extending from the firstend to the second end, the latter end being connectable for fluidcommunication via a flexible tubing to a suction source in order topermit evacuation of surgical smoke and debris. An elongate vent tube ismounted in the airflow vent and slidable therein. The position of thistube is adjustable in its longitudinal direction from a retractedposition to a selected one of a plurality of extended positions where aforward end of the vent tube is located forwards of the first end of themain body. There is also an elongate electrode suitable for performingelectrosurgery mounted in the vent tube and independently slidabletherein. The position of this electrode is adjustable in itslongitudinal direction between a retracted position and a selected oneof a plurality of extended positions where a forward section of theelectrode projects forwards from both the first end of the main body andthe forward end of the vent tube. The tool includes an electrical switchfor the tool connectable to an electrical control for the tool. The toolis characterized in that the electrical switch is mounted on the bodyportion, the position of the electrode is adjustable by pulling on aprojecting forward section of the electrode, and the vent tube is openat its forward end. A first metal conducting strip is mounted in thevent tube and is in electrical contact with the electrode in any of theplurality of extended positions. A second metal conducting strip ismounted in the main body and adjacent to the vent tube. The two metalconducting strips are in sliding electrical contact with one another.The second conducting strip is adapted to electrically connect the firstconducting strip to the electrical control.

In an exemplary version of this electrosurgical tool, a metal connectoris mounted on a rear section of the electrode and a bent metalconducting tongue extends from the metal connector to the first metalconducting strip to provide an electrical connection that is slidablealong the first conducting strip.

According to another aspect of the present application, anelectrosurgical tool for use with a power source and a suction sourceincludes an elongate body forming a handle for a user and an airflowvent extending from an open first end to an open second end which isconnectable during use of the tool to the suction source. An elongatevent tube having a front end and rear end section open to the airflowvent is slidably mounted in the airflow vent for longitudinal movement.The position of the vent tube is adjustable longitudinally relative tothe body. The vent tube has a front end section which projects forwardlyfrom the first end of the body by an amount which is adjustable by auser of the tool. There is also provided an elongate electrode forperforming surgery mounted in the vent tube and movable longitudinallyrelative to both the vent tube and the body. The electrode in use has aforward section projecting from the front end of the vent tube and isconnected to the power source. An electrical circuit board is providedto control electrical operation of the electrode and is mounted in thebody and connectable to the power source. The circuit board has a metalelectrical connector mounted at one end of the board. A metal conductingstrip is mounted in the elongate body and has a bent end sectionelectrically connected to the metal connector. An elongate metalconducting member is mounted in the vent tube as is in sliding contactboth with the electrode and the metal conducting strip.

In an exemplary version of this tool, the vent tube is formed internallywith two longitudinal, spaced-apart rib-like connectors for the metalconducting member which is another conducting strip. These rib-likeconnectors extend at least a major portion of the length of the venttube.

In a still further embodiment of the present application, anelectrosurgical tool for use with an electrical power source and asuction source includes a body forming a handle for a user and anairflow vent extending rearwardly from an open front end of the body andhaving an outlet connectable to the suction source. The tool has anelongate vent tube for evacuating smoke or debris from a surgical site,this tube having a front end and outlet opening into the airflow vent.The vent tube is slidably mounted in the airflow vent for longitudinalmovement and has a front section projecting forwards from the front endof the body. The length of the front section is manually adjustable by auser of the tool. An elongate electrode device for performing a surgicaloperation is mounted in the vent tube and slidable therein in thelongitudinal direction relative to both the vent tube and the body. Theelectrode device in use projects from the front end of the vent tube andis operatively connected to the power source. This electrosurgical toolis characterized in that the front end of the vent tube is open and aseparate metal connector is mounted on a rear section of the electricaldevice and has a bent metal conducting tongue extending from an endthereof. An elongate metal conducting member is mounted within the venttube and extends longitudinally therein. The bent tongue slidinglyengages the elongate conducting member. A further elongate metalconductor operatively engages the metal conducting member and is adaptedto provide an electrical connection between the electrical conductingmember and the power source. The tool also has a slide restrictingmechanism for limiting sliding movement of the electrode device in alongitudinal direction relative to the vent tube and the body. The sliderestricting mechanism acts to restrict movement of the electrode deviceunless sufficient force is applied to the vent tube in the longitudinaldirection.

In a particular embodiment, the slide restricting mechanism is anelectrode support member mounted on a rear section of the electrode andslidable therewith. This support member has radially projecting armswhich engage an interior surface of the vent tube in a manner causing afriction fit.

Other advantages, features and characteristics of the presentelectrosurgical pencil will become apparent upon consideration of thefollowing detailed description and the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

Reference will now be made, by way of example, to the accompanyingdrawings which show sample embodiments of the present application, andin which:

FIG. 1 is a perspective view of a first embodiment of electrosurgicalpencil constructed according to the present application, this view beingtaken from above and from the right side;

FIG. 2 is a top view of the electrosurgical pencil;

FIG. 3 is a longitudinal vertical cross-section of the pencil takenalong the line of FIG. 2 with the vent tube not in cross-section;

FIG. 4 is a longitudinal cross-section similar to FIG. 3 but showing thevent tube in cross-section;

FIG. 5 is a top view of the vent tube of FIG. 4 shown separately;

FIG. 6 is a side view of the vent tube showing interior details in dashlines;

FIG. 7 is a front end view of the vent tube of FIG. 6 ;

FIG. 8 is a detail perspective view of a rear section of the vent tube,this view being taken from above and from the rear of the tube;

FIG. 9 is a perspective view of a tubular support member mounted at therear end of the electrode;

FIG. 10 is a side view of the support member of FIG. 9 ;

FIG. 11 is a front end view of the support member of FIG. 9 ;

FIG. 12 is a first side view of a first version of a metal connector forattaching a wire to the electrode;

FIG. 13 is a second side view of the metal connector as seen from theright side of FIG. 12 ;

FIG. 14 is a detail perspective view of one-half of the inside of themain body of the pencil, this view showing the region where the circuitboard and electrical switch are mounted;

FIG. 15 is another detail perspective view of one-half of the inside ofthe main body portion of the pencil showing the region where the circuitboard and switch are mounted;

FIG. 16 is a cross sectional detail showing a ball joint for connectinga rear end socket section of the pencil to flexible tubing;

FIG. 17 is a detail view in perspective of one-half of the socketsection formed at the rear end of the main body portion;

FIG. 18 is a detail view in perspective of the other half of a socketsection at the rear end of the main body portion; and

FIG. 19 is a partial cross section of another embodiment of anelectrosurgical pencil according to the application with the right halfof the pencil (bottom half as viewed in FIG. 19 ) shown in cross sectionto show internal features

FIG. 20 is a longitudinal side view of the vent tube used in the pencilof FIG. 19 ;

FIG. 21 is a perspective view of the vent tube shown in FIG. 20 , thisview being taken from above and from the rear end;

FIG. 22 is a longitudinal cross section of the second embodiment takenalong the line XXII-XXII of FIG. 19 ;

FIG. 23 is a perspective view partly in vertical cross sectionillustrating one form of mounting of a first version of the circuitboard and switch in the main body of the pencil;

FIG. 24 is a detail side view of a spring clip attachment that connectsto the rear end of the electrode blade in the embodiment of FIG. 19 ;

FIG. 25 is a front end view of the pencil of FIG. 19 ;

FIG. 26 is a detail elevation showing how ratchet teeth on one form ofthe vent tube are engaged by the spring clip attachment on the blade;

FIG. 27 is a transverse cross section of the pencil of FIG. 19 , thisview being taken along the line XXVII-XXVII of FIG. 19 ; and

FIG. 28 is a longitudinal cross-section similar to FIG. 4 but showing athird embodiment of an electrosurgical pencil;

FIG. 29 is an exploded view of the pencil of FIG. 28 , this viewomitting a right half of the main body, the circuit board and thecontrol switch;

FIG. 30 is a perspective view taken from above illustrating theelectrical control switch used in third embodiment;

FIG. 31 is a perspective view taken from above showing the circuit boardused in the third embodiments of the pencil;

FIG. 32 is a perspective view taken from above and from the rear showingthe rubber pad used in the ESU pencil of FIG. 28 ;

FIG. 33 is a detail view showing a central section of a left half of themain body portion of the pencil;

FIG. 34 is a detail view of forward section of the left half of the mainbody portion;

FIG. 35 is a top view of the vent tube shown in FIG. 29 ;

FIG. 36 is a longitudinal cross-section of the vent tube taken along theline XXXVI-XXXVI of FIG. 35 ; and

FIG. 37 is a front end view of the vent tube of FIG. 35 .

DETAILED DESCRIPTION

FIGS. 1 to 4 illustrate a first embodiment of an electrosurgical pencil10 constructed in accordance with the application. FIGS. 5 to 8illustrate an elongate vent tube 12 for use in the pencil 10. Theelectrosurgical pencil 10 is for use in performing surgery on a surgicalsite, this pencil including a main body portion 14 forming a handlegrippable by a user, for example a surgeon. The main body portion isshaped for ease of comfort by the user. The body portion 14 includes anopen electrode end 16 and an open exhaust end 18. The main body portionis made from a suitable plastic material, such as polyethylene, and itcan be constructed from two half sections 20,22 that extend the lengthof the main body portion. These half sections can be rigidly andpermanently attached to each other by such known methods as ultrasonicwelding or adhesive bonding. It should be noted that the pencil 10 isintended for one time use only and is disposed of after surgery.

The main body portion has an internal longitudinal wall structure 24that together with outer walls of the half sections 20,22 form anelongate airflow vent 26 extending from the electrode end 16 to theexhaust end 18. As illustrated in FIG. 4 , the vent 26 has a widersection 28 adjacent to the exhaust end and this section includes arounded ball socket 30 which receives a separate ball-swivel member 32shown in greater detail in FIG. 16 .

The main body portion includes transverse support walls 36,38,40viewable in FIG. 4 plus a couple of short transverse walls 48,50 visiblein FIGS. 14 and 15 . The short transverse walls 48,50 support a circuitboard 52 illustrated in FIGS. 3, 4 and 23 . In an alternateconstruction, the walls 48, 50 can be omitted. The circuit board is forregulating and controlling electrical operation of an elongate, heatableelectrode tool 54 which either can be in the form of a scalpel or blade(as shown) or a needle. An electrical switch mechanism 56 is mounted onthe main body portion 14 so as to be operable externally on the mainbody portion and the circuit board is operated by this switch mechanism.The switch 56 can be a rocker switch similar to that used in applicant'sprior U.S. Pat. No. 6,616,658. The switch 56 is a single-pole,double-throw rocker type electrical switch mounted on top of the bodyportion and above the circuit board 52. The illustrated switch has twodownwardly projecting pins 58, 60 which project through two holes in arecessed section 62 of the main body portion. Round holes 64, 66 areformed near opposite ends of the recessed section 62. Only one-half ofeach of these holes is shown in FIGS. 14 and 15 . In use, the forwardend of the switch can be pressed by the surgeon to provide a higherfrequency signal to the electrode tool 54 for cutting tissue and therearward end of the switch 56 is pressed to provide a lower frequencysignal to the electrode tool for cauterizing tissue. The switch shown inFIG. 2 has molded lettering CUT and COAG formed thereon to clearlyindicate these two switch functions.

In the first embodiment of the pencil as illustrated in FIGS. 3 and 22 ,an insulated wire 70 enters an upper section of the main body portionthrough the ball-swivel member 32 and is connected to the circuit board52. The wire is electrically connected to one of the terminals operatedby the electrical switch mechanism while another terminal is connectedelectrically to the electrode tool by means of a second insulated wire72 shown in FIGS. 4 and 22 . The wire 72 is relatively thin so that itis highly flexible and bendable during use of the pencil.

FIGS. 5 to 8 illustrate a first embodiment of vent tube 12 which ispreferably made of transparent plastic and has an open front end 90 andan open rear end at 92. If desired, the front end can be cut or formedat an acute angle to the longitudinal axis of the tube. Smoke form asurgical site can pass through the entire length of this vent tube.Except for a short rear end section, the tube has a circular transversecross-section. Located at or near the front end of the tube is an eyeletguide 180 having a circular passage 182 through which the electrode toolextends as illustrated in FIG. 4 . The passage is formed by acylindrical section 184 which is coaxial with the central longitudinalaxis of the tube. Projecting radially outwardly from the cylindricalsection are integral connecting webs 186. The illustrated embodiment hasthree such webs but there could be fewer or more than three. Gaps oropenings are formed between the webs to allow for passage of smoke, etc.into and through the vent tube. The illustrated tube is formed with alongitudinal groove 188, the rear end of which is clearly visible inFIG. 8 . This groove extends a substantial portion of the length of thevent tube and its purpose is explained hereinafter. Its front end at 191acts as a stop to limit forward movement of the electrode as explainedbelow. A rear stop member 193 can be mounted in a slot near the rear endof the groove to prevent the electrode from exiting the rear end of thetube.

A tapering slot 190 is formed on a rear end section of the tube as shownin FIGS. 5 and 8 . The slot has a rounded forward end at 192. Thefunction of this slot is to accommodate passage of the insulated wire 72that is connected to the electrode tool. The slot allows the wire topass upwardly for connection to the circuit board at illustrated in FIG.4 and prevents the tube from interfering with the wire, particularlywhen the tube is moved rearwardly. Also the tube is formed with adownwardly projecting rib 194 that is parallel to and below theaforementioned groove 188. This rib can slide along a matching groove(not shown) formed along the bottom of the body portion 12 and thisengagement both prevents rotation of the tube relative to the bodyportion and also limits outward movement of the vent tube when the frontend of the rib meets the front end of the groove.

The rear end of the electrode tool 54 is supported in the tube by anelectrode support member 200 shown separately in FIGS. 9 to 11 and shownmounted on the rear end of the electrode tool in FIG. 4 . The exemplarysupport member has a tubular body 202 having a passageway 204 formedtherein and extending the length of the tubular body. The tubular bodycan slide over the rear end section of the electrode and it is rigidlyattached to the electrode via a metal connecting sleeve, such as theversion 218 shown in FIGS. 12 and 13 (described below) so that it isslidable therewith and will not rotate on the electrode. The supportmember 200 has radially projecting arms 206,208 and 210 which extend atan acute angle to the longitudinal central axis of the tubular body. Thearms are angled rearwardly towards the rear end 212 of the tubular body.The arm engages an interior surface 214 of the vent tube in a mannercausing a friction fit between the ends of the arms and the interiorsurface. The exemplary support member 200 is made of an electricallyinsulating plastic and this plastic is chosen so that the three arms aresomewhat resilient or bendable. This way the arms are made to pressagainst the interior surface of the tube. The result is that theelectrode tool normally maintains a selected position in thelongitudinal direction thereof relevant to the vent tube. In order wordsthe friction between the ends of the arms and the vent tube must beovercome by the user of the pencil in order to slide the electrode toolrelative to the vent tube. Although only three arms are shown in theFigures, it is possible for the support member to have more than threearms but the gaps between the arms must be sufficient to allow forproper flow of smoke and fluids through the vent tube.

The exemplary support member 200 has an arm 210 that projects rearwardlyand outwardly a greater distance than the other two arms because the arm210 is constructed to slide along the aforementioned groove 188 in thevent tube. The engagement between the arm 210 and the groove preventsrotation of the electrode about a central longitudinal axis of the venttube. This can be desirable, particularly if the outer end section ofthe electrode is not circular, for example if it is blade shaped and theblade is to be maintained in a certain orientation.

FIGS. 12 and 13 illustrate one form of a metal connecting sleeve 218which can be used to connect the aforementioned insulated wire 72 to therear end of the electrode tool. The sleeve 218 is made of a metalconductor such as brass and can be formed from a single sheet of thinmetal. The sleeve has a tubular body 220 forming a passageway 222 sizedto snuggly receive a rear end section of the electrode. Formed in twoopposite sides of the tubular body are two spring arms 224,226 which areformed to extend slightly into the passageway. The wire 72 is connectedto the rear end section 232 of the connecting sleeve. The end of thesleeve opposite the tab can be flared at 232 for relatively easyinsertion of the electrode into the rear end of the sleeve. The U-shapedsection 232 is formed so as to be pressed around and clamped to the endof the wire 72. This section has two bendable parallel arms, 234,236.The rear section of the electrode is formed with two flat indentationson opposite sides of the electrode (not shown). The rear section of theelectrode is inserted into the connecting sleeve until the arms 224,226engage their respective flat surfaces of the electrode, thereby holdingthe connecting sleeve and surrounding support member 200 securely inplace.

Reference will now be made to FIG. 16 which shows details of the ballsocket 30 and the ball-swivel member 32 which can pivot in the ballsocket. The ball-swivel member 32 has a ball portion 120 integrallyconnected to a tubular section 122. A straight internal passage 124extends the length of the ball-swivel member 32 and this passage has aninner end at 125 which is always open to the airflow vent 26 formed inthe main body portion 14. Annular ridges 126 can be formed on thetubular section in order to engage and hold an end section of flexibletubing such as ⅜ inch plastic tubing (not shown). Provided on theexterior of the tubular section or nipple 122 is an outwardly projectingannular ridge 130 which acts as a stop for the end of the plastic hose.The ball socket 30 can be provided with two annular ridges 132,134 whichproject inwardly so as to engage the spherical surface of the ballportion 120. These ridges help to seal the joint between the ballportion and the ball socket 30 as well as facilitate the pivoting motionof the ball portion in the socket.

In one exemplary embodiment of the present pencil 10, the passage 124 inthe member 32 has a diameter of 0.32 inch while the ball portion 120 hasan external diameter of 0.5 inch. This ball connection enables greatflexibility in maneuvering the pencil 10 during an operation which canbe important when carrying out a delicate operation.

FIGS. 17 and 18 illustrate how the two ridges 132,134 are formed by twosemi-annular sections, one section on each of the half-sections 20, 22.Also illustrated in these views are integral support formations 140-143located close to the ball socket. From the two formations 140,141 extendrespective plastic pins 144 which can be integrally formed with the halfsection. Corresponding pin receiving holes 146 are formed in supportformations 142 and 143. When the two half-sections are placed togetherto form the main body portion, the pins 144 extend into the two holes146 and can be ultrasonically welded in the holes. In addition to thisconnection there is a tongue and groove connection between the two halfsections 20, 22. Tongues 150 can be formed along opposite side edges ofthe half section 20 while a corresponding, matching groove 152 can beformed along opposite side edges of the half section 22. The tongues 150are permanently secured in the grooves by the ultrasonic weldingoperation or by adhesive.

As noted, both the longitudinal position of the electrode tool and thatof the vent tube 12 are independently adjustable. It is generallyunderstood that for best evacuation of smoke from an operating site, thefront end of the vent tube 12 should be within ½ inch of the operatingend portion of the tool. This preferred relative position can beobtained with the present pencil 10. As indicated above, insulatingplastic material extends for most of the length of the blade but thefront end section is exposed for the coagulation of blood vessels.

Under some circumstances, a surgeon may wish to withdraw the vent tubefurther away from the exposed front end section of the electrode bladein order, for example, to provide greater visibility of this front endsection.

One construction for providing a friction mechanism to hold the venttube in place is illustrated in FIGS. 3, 4 and 22 . This constructioninvolves the use of a rubber or rubberlike friction member 170 mountedin a chamber of the body portion 14 formed by internal transverse walls36 and 38, in the body of FIGS. 3 and 4 and by transverse walls 39,41 inthe body of FIG. 22 . This chamber, which holds the friction member, isopen towards the vent tube so that the inner side of the friction memberengages the side of the vent tube. In an exemplary version, the innerside of the friction member is formed as a concave surface with acurvature corresponding to the exterior of the vent tube. The vent tubewill generally hold the position to which it is pulled or pushed by theuser. In an alternate construction, an O-ring is mounted around the ventfor providing the friction mechanism.

FIGS. 19, 22 and 23 illustrate a second embodiment of an electrosurgicalpencil 10′ constructed in accordance with the application. FIGS. 20 and21 illustrate an elongate vent tube 12′ for use in the pencil 10′. Thispencil also has a main body portion 14 similar to that in the firstembodiment described above. The pencil 10′ is similar to theelectrosurgical pencil 10 except for the differences noted hereinafterwith respect to its construction and its method of operation.

In the second embodiment 10′ the illustrated wire 72 which is connectedto the electrode tool is connected to same by means of a spring clip 74which is shown separately in FIG. 24 . The spring clip shown in FIG. 24is formed with a passage 76 through which a rear end section of theelectrode tool of the second embodiment of the pencil extends.

The spring clip is made of a suitable electrically conductive metal soas to transfer the electrical current from the wire 72 to the electrodetool. Arranged at one end of the spring clip is a wire clamp 78 forsecuring the end of the wire 72. Arranged on top of the spring clip is aratchet engaging member 80 having a concave top surface 82 for engagingbumps on a ratchet formation 84 on the exterior of the rear section ofthe vent tube 12′ (see FIGS. 19, 20 and 22 ). It will be understood thatthe manner in which the electrode tool is mounted in the vent tubeallows its longitudinal position relative to the vent tube to beadjusted as desired by the user. The ratchet engaging member 80 and theratchet formation 84 together form a ratchet mechanism for limiting andpreventing unwanted sliding movement of the electrode tool 54 relativeto the vent tube 12′ of the second embodiment.

The vent tube 12′ used in the pencil 10′ will now be described withparticular reference to FIGS. 20 to 23 . The illustrated vent tube,which preferably is made of transparent plastic, has an open front endat 90′ and an open rear end at 92′. The tube has a front section 94 witha circular transverse cross section and a rear section 96 which has arounded exterior except for a substantially flat top portion 98.Extending at least most of the length of the top portion 98 is a centrallongitudinal slot 100 visible in FIG. 21 . Located near the front end90′ of the tube is an eyelet guide 102 having a circular hole throughwhich the electrode tool extends as illustrated in FIG. 22 . It will beunderstood that the eyelet guide 102 provides support for a forwardportion of the electrode tool while the rear end of the electrode toolis supported by means of the spring clip 74. As known in the art, theelectrode tool is covered by an insulating plastic along a substantialcentral portion of its length (see FIG. 29 ). This insulating cover canextend through the guide 102. In order for the spring clip to providesupport, a narrow section of the ratchet engaging member 80 extendsthrough the slot 100 as shown in FIG. 26 . The top section of the member80 is wider than its bottom section and wider than the width of the slot100. This arrangement provides a slidable support for the rear end ofthe electrode tool which is not covered by insulating plastic. The widerupper portion of the member 80 engages the ratchet formation 84 formedon the top of the top portion 98 of the vent tube and thus acts toprevent unwanted sliding movement of the blade while still allowingrelative movement between the blade and the tube.

Instead of using the rubber friction member 170 described above, asuitable O-ring (not shown) can be mounted between the outer surface ofthe vent tube 12′ along a rear portion of the front section 94 and thewall of the airflow vent 26 in order to provide both a seal around thevent tube and a friction fit that prevents unwanted relative movementbetween the vent tube and the main body portion 14. Alternatively therecan be a close, friction fit between the vent tube and the airflowpassage through which it extends so that the vent tube will not moverelative to the main body portion unless manually pulled or pushed bythe user.

An optional feature which can be included in either electrosurgicalpencil described above is a lighting device to enable the surgeon orother user of the pencil to better see the operating site. Two possiblealternatives for providing this lighting are illustrated in FIG. 22 ,the first being the use of one or more LED lights 160 mounted at theelectrode end of the main body portion above the vent tube. The light orlights are connected to a small standard battery 162 located in aforward chamber 164 of the body portion 14. A standard electrical switch(not shown) can be used to close the circuit between the battery and theLED light 160.

As an alternate to the aforementioned lighting arrangement, a ring ofLED lights 166 can be mounted at the open rear end of the vent tube in amanner so that the lights do not interfere with airflow through the venttube or with the passage of the wire 72 into the vent tube. The array orring of lights at 166 can be powered by the battery 162 through asuitable wire connection (not shown) or they can be powered by the sameelectrical source as the circuit board with this power being receivedthrough the wire 72 or a branch thereof. If the vent tube is made ofclear transparent plastic, the light from the lights 166 will betransmitted down the vent tube to the surgical site.

FIGS. 28 and 29 illustrate a third embodiment of an electrosurgicalpencil 240. The construction and operation of this pencil 240 is similarto the pencil 10 illustrated in FIGS. 1 to 4 except for the differencesnoted and described hereinafter. This pencil has a main body portion 14forming a handle grippable by a user, only one half of which is shown inthe exploded view of FIG. 29 . The main body portion has an internallongitudinal wall structure 24 similar to that in the first embodiment.However, formed on the upper surface of this wall structure are a seriesof transverse ridges 242 on which is mounted the circuit board 52, whichis shown separately in FIG. 31 . An alternate form of electrical switchmechanism 244 is mounted on the main body portion in a manner thatallows it to be used to operate the circuit board. As with the switchmechanism 56, the switch mechanism 244 is also a rocker switch and isshown separately in FIG. 30 . This switch mechanism also has twodownwardly projecting pins 58, 60 which project through two holes formedin the recessed section 62 of the main body portion. In the switchmechanism 56 of the first pencil embodiment, the mechanism is connectedto the main body of the pencil by two flexible clip mechanisms 56, 59illustrated clearly in FIG. 14 . Each of the clip mechanisms comprisestwo spaced apart arc-shaped clip members 61, 63. Each of these membersis formed with a bottom edge having an outwardly projecting flange 65.Because of the flexibility of the clip members, it is possible to pushthese through the round holes 64, 66 in order to attach the switch 56 tothe main body portion. It will be understood that the external diameterof the two cooperating edge flanges exceeds the diameter of theirrespective hole, 64, 66 so that when these flanges pass through thehole, they will retain the switch in place.

The switch mechanism 244 shown in FIGS. 28 and 30 is of similarconstruction except that instead of only two clip members for each clipmechanism, there are four similar clip members 246 distributed evenlyabout the projecting pin 58, 60. Again each clip member is formed withan outwardly projecting bottom flange 248 and the four bottom flanges ofeach clip mechanism will cooperate together to hold their respective endof the switch in place on the body portion of the pencil. As shown inFIG. 33 the edge of each hole 64,66 preferably has a lead-in chamfer 320to facilitate insertion of the clip members through the holes.

It will be understood that the circuit board 52 is connected to a powersource by insulated wire 70 (not shown in FIGS. 28 and 29 ) similar tothe wire 70 shown in FIGS. 3 and 4 . However, the conducting arrangementfor providing electrical power to the electrode tool is different in thepencil 240. In this pencil, there is a first metal conducting strip 250which is mounted in the vent tube 12 and is in electrical contact withthe electrode tool 54 in any of a plurality of extended positions. Inaddition, there is a second metal conducting strip 252 which is mountedin the main body portion 14 directly below the wall structure 24 andadjacent to the vent tube. The two metal conducting strips are insliding electrical contact with one another and the second metalconducting strip 252 is adapted to electrically connect the first metalconducting strip 250 to the electrical control provided by the circuitboard.

The exemplary conducting strip 250 illustrated in FIG. 29 has an upwardprojecting end section 254. The strip 250 bends upwardly at 256 and thenbends rearward to form a short flat section 258, which extends generallyparallel to the main body of the conducting strip 250. The end sectionalso has a downwardly extending end flange at 260. The vent tube 12 asshown in FIGS. 29, 35 and 36 is modified to accommodate the conductingstrip 250. In particular, it is formed with a rectangular opening 262 onits top side. The opening 262 is formed in a rear end section of thevent tube 12. The upwardly bent rear end section 254 is sized to fitthrough the opening 262 and to project there from so as to slidinglyengage the second metal conducting strip 252 as shown in FIG. 28 . Theend flange 260 is pushed into a transverse slot 264 also formed on thetop side of the vent tube. The flange engagement holds the strip 252 inplace, preventing longitudinal movement of the strip.

In addition, in order to hold the conducting strip 250 in place, thevent tube 12 of the third embodiment is formed internally with twolongitudinal, spaced-apart rib-like connectors, 266, 268 that extend atleast a major portion of the length of the vent tube as shown in FIG. 36. These rib-like connectors capture the longitudinal edges of theconducing strip 250. It will also be appreciated that instead of arelatively flat conducting strip 250, this first conducting member canbe constructed differently, for example in the form of an elongate metalconducting member such as a suitable conducting wire having a roundcross section. Such a wire can be captured in a single slot formed onthe upper side of the tube. The exemplary second metal conducting strip252 is formed with a bent back end section 270. As illustrated in FIG.28 , the end section 270 extends around the forward end of the wallstructure 24. The end section 270 can be formed with a relativelynarrow, rearwardly projecting tongue 272 which projects into the sleeveof an electrical connector 274 mounted on the forward end of the circuitboard 52 (see FIG. 31 ). In this way power from the circuit board isprovided to the second conducting strip 252 which is then able totransmit this power to the first conducting strip 250 whatever extendedposition of the vent tube 12 is selected. The two strips 250,252 can bemade of brass.

A different form of metal connector that acts as an electrical conductoris used in the ESU pencil 240 as compared to the metal connecting sleeve218 shown in FIGS. 12 and 13 and described above. In particular, a metalconnector 280 is mounted on the bare, electrically conducting, rearsection 282 of the electrode tool. The connector 280 has a bent metalconducting tongue 284 that extends from the metal connector to the firstmetal conducting strip 250 to provide an electrical connection slidablealong this conducting strip 250. The main portion of the metal connector280 is in the form of a split sleeve 288 able to expand sufficiently tofit snugly on the rear conducting section 282 of the electrode tool. Thebent conducting tongue 284 is formed initially as a straight, elongatetongue projecting rearwardly. In this form the conductor is telescopedover the rear section 282. Then the electrode support member 200 ispushed over the split sleeve 285 until it rests against the shoulder 290formed on the electrode by its plastic covering. In this way the supportmember 200 holds the connector 280 firmly in place on the rear sectionof the electrode. The rearwardly projecting tongue of the connector canthen be bent in the forwards direction and then rearwards to form aspring-like contact that can slide along the adjacent surface of theconducting strip 250. FIG. 32 illustrates an exemplary form of the abovedescribed rubber friction member 170. This friction member is mounted inthe main body portion 14 near the forward end as shown in FIG. 28 . Ithas an inner surface at 292 in the form of a cylindrical arc having aradius corresponding to the external radius of the vent tube. This innersurface engages the upper side of the vent tube and presses against samein order to restrict the sliding movement of the vent tube in itspassageway. An upper surface 294 of the friction member or pad can alsobe curved and this surface tapers from the rear end 298 to the front end300 so that the pad can fit within the tapered front section of the mainbody of the pencil.

The support for the forward section of the electrode tool 54 alsodiffers in the third version of the ESU pencil compared to the firstembodiment of the pencil. Instead of the support arrangement shown inFIG. 7 having the cylindrical section 184, there are formed in theforward section of the vent tube a plurality of longitudinal guide ribs306. As shown in FIGS. 36 and 37 , there are three such guide ribsdistributed evenly about the circumference of the vent tube, that is, atangles of about 120 degrees to one another. The electrode or electrodetool extends through a central passage 308 defined by the guide ribs andis slidably supported by these guide ribs.

FIGS. 33 and 34 also illustrate an exemplary feature for attaching thetwo half sections of the main body portion 14 to each other. Inparticular weld beads can be provided at 325,326 along top and bottomedges of one half of the main body portion. A further short weld beadcan be provided at 328 along the top edge that extends between holes64,66. A further weld bead can be provided at 330 along one half of theinternal wall structure 24. These weld beads fit into correspondinggrooves formed in the opposite half of the main body portion.

There is also shown in FIG. 34 one half of a projecting stop 332 that,together with the wall structure 24 forms a gap 334. Through this gapthe bent end section 270 of the second metal conducting strip 252extends in the assembled condition of the pencil. The stop 332 preventsany forward movement of the conducting strip 252 in its passageway.

While the present application has been illustrated and described asembodied in exemplary embodiments, e.g. embodiments having particularutility in surgical applications, it is to be understood that thepresent application is not limited to the details shown herein, since itwill be understood that various omissions, modifications, substitutionsand changes in the forms and details of the disclosed electrosurgicalpencils and their operation may be made by those skilled in the artwithout departing in any way from the scope of the present application.For example, those of ordinary skill in the art will readily adapt thepresent disclosure for various other applications without departing fromthe scope of the present application.

What is claimed is:
 1. An electrosurgical tool for performing a surgical procedure, comprising: an elongated body; an elongated vent tube mounted in the body and configured to move longitudinally relative to the body; an elongated electrode mounted in the vent tube and configured to move longitudinally relative to at least one of the vent tube or the body; a conducting member disposed outside of the vent tube and in the body; and a connector electrically coupled to the electrode and is axially fixed to the vent tube, the connector in sliding contact with the conducting member, such that the electrode and the conducting member are slidably, electrically connected to one another and the connector moves longitudinally with the vent tube.
 2. The electrosurgical tool according to claim 1, wherein the electrode is configured to move longitudinally relative to both the vent tube and the body.
 3. The electrosurgical tool according to claim 1, wherein the electrode has a proximal end section, the connector electrically coupled to the electrode.
 4. The electrosurgical tool according to claim 1, wherein the connector has a bent conducting tongue in sliding contact with the conducting member.
 5. The electrosurgical tool according to claim 1, further comprising a circuit board for controlling electrical operation of the electrode, the circuit board mounted in the body and connectable to a power source.
 6. The electrosurgical tool according to claim 5, further comprising an electrical connector mounted to the circuit board and electrically connected to the electrode via the conducting member and the connector.
 7. The electrosurgical tool according to claim 1, wherein the conducting member is axially fixed relative to the vent tube.
 8. The electrosurgical tool according to claim 1, wherein the vent tube has a proximal end section defining an opening in a top side thereof, the conducting member having an upwardly bent proximal end section extending into the opening.
 9. An electrosurgical tool for performing a surgical procedure, comprising: a main body; an elongated vent tube disposed in the main body, the vent tube having a wall that defines an opening through a thickness thereof; an elongated electrode disposed in the vent tube and configured to move longitudinally relative to at least one of the main body or the vent tube; a first conducting member electrically coupled to the electrode and restrained within the vent tube; and a second conducting member disposed outside of the vent tube and within the main body, wherein the first conducting member has a section that extends through the opening of the vent tube and into sliding contact with the second conducting member.
 10. The electrosurgical tool according to claim 9, wherein the electrode is configured to move longitudinally relative to both the vent tube and the main body.
 11. The electrosurgical tool according to claim 9, wherein the vent tube is configured to slide relative to and within the main body.
 12. The electrosurgical tool according to claim 9, wherein the wall of the vent tube has an outer surface, and an inner surface defining a longitudinally-extending passageway, the opening of the wall of the vent tube extending through the inner and outer surfaces of the vent tube.
 13. The electrosurgical tool according to claim 12, wherein the electrode is mounted in the passageway of the vent tube.
 14. The electrosurgical tool according to claim 9, wherein the section of the first conducting member is bent upwardly.
 15. The electrosurgical tool according to claim 9, further comprising longitudinal guide ribs mounted in the vent tube adjacent a distal end section of the vent tube.
 16. The electrosurgical tool according to claim 15, wherein the longitudinal guide ribs are circumferentially disposed on an internal surface of the vent tube.
 17. An electrosurgical tool for performing a surgical procedure, comprising: a main body; an elongated vent tube disposed in the main body, the vent tube having a wall that defines an opening through a thickness thereof; an elongated electrode disposed in the vent tube and configured to move longitudinally relative to at least one of the main body or the vent tube; a first conducting member electrically coupled to the electrode; and a second conducting member, wherein the first conducting member has a section that extends through the opening of the vent tube and into sliding contact with the second conducting member, wherein the first conducting member is axially fixed to the vent tube, such that the first conducting member moves longitudinally with the vent tube. 